Electric timepiece contact mechanism



Jan. 9, 1962 F. KOEHLER 3,015,933

ELECTRIC TIMEPIECE CONTACT MECHANISM Filed Aug. 15, 1958 INVENTOR FredKoeh/er ATTORNEY United States Patent 5 lvania y Filed Aug. 15, 1958,Ser. No. 755,198

6 Claims. (CI. 58-28) This invention relate to an electric timepiece andmore particularly relates to an improved adjustable mounting for thespring contact in a battery operated electric timeiece.

p In a battery operated electric timepiece of the type shown inassignees Patent No. 2,662,366 to Fred Koehler, a magnetic bar iscarried by the balance staff and is periodically impulsed by the polepieces of a pair of electro-magnets. The periodic impulses are createdby cyclically connecting the electro-magnets to the battery and thisperiodic connection is accomplished by a sprmg contact mechanism.

In the type watch shownin the aforementioned Koehler patent, thiscontact mechanism consists of an elongated contact spring which isfixedly mounted at one end and which carries a movable contact at itsother end. A 'camrning means is attached to an intermediate portion ofthe spring and periodically forces the free end carrying the contactsinto engagement with stationary contacts. The elongated spring extendspast the index wheel of the timepiece and the camming means on thespring engages the teeth of the index wheel so as to cause the desiredmovement of the contact-carrying end of the spring as the index wheel isrotated under control of the balance staff and its associated parts.

The tension with which the contact spring cam presses against the teethof the index wheel is somewhat critical in that this tension serves thedual purpose of holding the index wheel in position between impulsesfrom the balance staff and also breaking the electric contact. If thetension of the spring is too low, it can cause the contact to stick andcan also cause the sweep second hand of the timepiece to run away whenthe hands of the timepiece are set to time. Too high a tension requiresexcessive energy to move the index wheel and results in a low motion ofthe balance wheel.

In the Koehler type timepiece shown in the aforementioned patent, theadjustment of the tension in the contact spring is initially made at thefactory and is: not readily changed except by returning the timepiece tothe factory. In those instances where it is necessary for jewelers toupset the tension, it is difiicult to reset it to the proper valuewithout returning the timepiece to the factory.

It is accordingly a primary object of the present invention to providean improved battery operated timepiece of the type generally shown inthe aforementioned Koehler patent having an improved mounting of thecontact mechanism which permits of accurate adjustment of the contacttension.

It i another object of the invention to provide a battery operatedelectric timepiece of the foregoing type where an adjustment of thecontact mechanism may be made by the average jeweler without thenecessity of returning the timepiece to the factory.

It is another object of the invention to provide a battery operatedelectric timepiece of the foregoing type wherein the tens-ion of thecontact spring is clearly indicated on a suitable indicia in thetimepiece, so that a jeweler may return the setting of the tension toits original value if it once is altered.

It is a still further object of the invention to provide an improvedcontact mechanism of the foregoing type Patented Jan. 9, 1962 "ice whichis simple in construction and economical of manufacture.

These and further objects andadvantages of the invention will becomemore apparent upon reference to the following specification and claimsand the appended drawing in which the sole figure is a partial plan viewof a battery operated electric timepiece of the type shown in KoehlerPatent No. 2,662,366 incorporating the contact mechanism of the presentinvention.

Referring to the figure of the drawing, there are shown twoelectro-magnet coils 10 and 12 mounted on the legs 14 and 16 of a core18. Pole pieces 20- and 22 extend inwardly from the ends of the legs 14-and 16 and are preferably of the bifurcated type shown in assigneescopending application Serial No. 743,370, filed June 20, 1958.

The balance staff 24 is mounted between the pole pieces 20 and 22 andcarries the magnetic bar 26 which is shown in phantom. The pole pieces20 and 22 are preferably bifurcated so that the ends of the bar 26 passbetween the bifurcations. The balance stalf carries a roller 28 having aslot 30- therein which receives the vertical end 32 of a spring carriedby the balance staff in the manner shown in detail in the aforementionedKoehler patent. The end 32 of this spring is free to move in the slot30' to perform the indexing function in the manner described in thatpatent. The toothed index wheel is pivoted at 36 in a bridge 38 coveringthe train of the timepiece. The spring end 32 engages the teeth of theindex wheel 34 and advances the index wheel in a clockwise direction asthe balance staff oscillates.

The construction discussed thus far has been previously described inKoehler Patent No. 2,662,?) 66 and in assignees aforementionedapplication, Serial No. 743,370. The subject matter of the instantinvention resides in the mounting of the elongated contact spring 40.

As in the timepiece shown in the Koehler patent, the contact spring 40carries a cam 42 intenmediate its ends and this cam may be formed of ajewel or of a suitable metal such as carbo-loy. The end of the spring40' carries a suitable contact 44 for engagement with the stationarycontact of the timepiece (not shown) as in the timepiece shown in theKoehler patent. Each time that the index wheel 34 is advanced one toothin a clockwise direction, the tooth engaging cam 42. urges the spring 40downwardly in the figure of the drawing, so that the movable contact 44engages the stationary contact of the timepiece to energize theelectro-rnagnets and thereby magnetically attract the bar 26.

According to the invention the end 46 of the spring 40 is connected inany suitable manner, such as by welding, to the end 48 of an arm 50. Thearm 50 is pivotally secured to the bridge 38 at 52 and is provided witha pointer 54 at its opposite end. Suitable indicia 56 are provided onthe bridge 38 to cooperate with the pointer 54 to indicate the positionof the arm 50. A locking screw 58 passes through a slot 60 in the arm 50and screwthreadedly engages the bridge 38. The bridge 38 is arcuatelycut away at 62 to permit pivotal movement of the end 48 of lever 50about pivot 52.

It will be apparent that the position of the lever 50 determines. thetension with which the cam 42 is urged against the index wheel 34. Oncethe tension is properly set the locking screw 58 may be tightened tolock the lever in position, and this position may be accurately noted orrecorded by means of pointer 54 and indicia 56. If it is subsequentlynecessary for a jeweler to upset the setting of the lever 50 for onetype of repair or another, it is possible toaccurately reset the tensionby simply returning the pointer 54 to the same position which itoccupied before the original adjustment was upset. In this manner itbecomes possible for jewelers to adjust the contact tension whichheretofore has been adjustable only at the factory. r

It will be apparent that the mounting of the contact spring providedaccording to this invention is simple of adjustment and permits ofaccurate return to an original factory made setting. The construction iseconomical while at the same time providing material advantages ineliminating the necessity for return of timepieces to the factory.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiment is therefore to be considered in all respects as illustrativeand not restrictive, the scope of the invention being indicated by theappended claims rather than by the foregoing description, and allchanges which come within the meaning and range of equivalency of theclaims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States LettersPatent is: I

1. 'In a combined contact and index mechanism for an electric timepiece,a toothed index wheel, an elongated contact carrying spring extendingpast said index wheel, cam means attached to said spring intermediateits ends and engaging said index wheel, a lever attached to one end ofsaid contact spring, and means pivotally mounting said lever on saidtimepiece for adjustment of the tension with which said cam meansengages said index wheel.

In a combined contact and index mechanism for an electric timepiece, atoothed index wheel, an elongated contact carrying spring extending pastsaid index wheel, cam means attached to said spring intermediate itsends and engaging said index wheel, a lever attached to one end of saidcontact spring, means pivotally mounting said lever in saidtimepiece foradjustment of the tension with which said cam means engages said indexwheel, and locking means for locking said lever in position.

3. In a combined contact and index mechanism for an electlic'timepiece,a toother index wheel, an elognated contact carrying spring extendingpast said index wheel,

cam means attached to said spring intermediate its ends and engagingsaid index wheel, a lever attached to one end of said contact spring,means pivotally mounting said lever in said timepiece for adjustment ofthe tension with which said cam means engages said index wheel, lockingmeans for locking said lever in position, and indicia means cooperatingwith said locking means to accurately indicate the position of saidmounting means.

4. In a combined contact and index mechanism for an electric timepiece,a toothed index wheel, an elongated contact carrying spring extendingpast said index wheel, cam means attached to said spring intermediateits ends and engaging said index Wheel, a mounting member attached toone end of said cont-act spring, means pivotally mounting said mountingmember in said timepiece for adjustment of the tension with which saidcam means engages said index wheel, locking means for locking saidmounting member in position, and indicia means cooperating with saidlocking means to accurately indicate the position of said mountingmeans, said mounting member comprising a lever pivoted intermediate itsends to the framework of said timepiece, said end of said contact springbeing connected to one end of said lever.

5. A mechanism asv set out in claim 4 wherein said lockingmeanscomprises a screw passing through a slot in said mounting member andscrewthreadedly engaging said framework of said timepiece.

6. A mechanism as set out in claim. 5 wherein the other end of saidlever comprise a pointer and said indioi-a comprises a scale on saidframework beneath said pointer.

References Cited in the file of this patent UNITED STATES PATENTS835,516 Giroud Nov, 13, 1906 2,125,638 Hubert Aug. 2, 1938 2,626,500Westlake Jan. 27, 1953 FOREIGN PATENTS 19,015 Great Britain July 7, 1904

